This no longer works in the latest version:

$extrafields = K2ModelItem::getItemExtraFields($this->item->extra_fields);

Read the notes on 2.6.2. The new call also does not work.

Have in item.php:

$video_type = $this->item->extraFields->Type->value;
$video_file = $this->item->extraFields->VideoURI->value;
echo $video_type;
echo $video_file;

where Type and VideoURI are the aliases of the fields in the template.

The output is null

opened each field, saved and closed. and it seems to work now.